Cascaded converged power amplifier

Patent metadata

Field	Value
Publication number	US-8942651-B2
Application number	US-201213656997-A
Country	US
Kind code	B2
Filing date	Oct 22, 2012
Priority date	Apr 20, 2010
Publication date	Jan 27, 2015
Grant date	Jan 27, 2015

Abstract

A first radio frequency (RF) power amplifier (PA) stage, a second RF PA stage, and an alpha RF switch are disclosed. The first RF PA stage provides a first RF output signal. During a first alpha mode, the alpha RF switch forwards the first RF output signal to the second RF PA stage, such that the first RF PA stage functions as a driver stage and the second RF PA stage functions as a final stage. However, during one of a group of alpha modes, the alpha RF switch forwards the first RF output signal to provide a corresponding one of a group of alpha transmit signals, such that the first RF PA stage functions as a final stage. Further, the first alpha mode is not one of the group of alpha modes.

First claim

What is claimed is:

1. Circuitry comprising:
a first radio frequency (RF) power amplifier (PA) stage adapted to provide a first RF output signal;
a second RF PA stage; and
an alpha RF switch adapted to:
during a first alpha mode, forward the first RF output signal to the second RF PA stage, such that the first RF PA stage is further adapted to function as a driver stage and the second RF PA stage is adapted to function as a final stage; and
during one of a plurality of alpha modes, forward the first RF output signal to provide a corresponding one of a group of alpha transmit signals, such that the first RF PA stage is further adapted to function as a final stage and the first alpha mode is not one of the plurality of alpha modes, wherein a load line of the first RF PA stage during the first alpha mode is not equal to any load line of the second RF PA stage during any of the plurality of alpha modes.

2. The circuitry of claim 1 further comprising a first alpha harmonic filter coupled to the second RF PA stage, such that during the first alpha mode, the second RF PA stage is further adapted to amplify the forwarded first RF output signal to provide a first alpha RF transmit signal via the first alpha harmonic filter.

3. The circuitry of claim 1 wherein the first alpha mode is a first alpha non-linear mode and the plurality of alpha modes is a plurality of linear modes.

4. The circuitry of claim 3 wherein the first alpha non-linear mode is a half-duplex mode and each of the plurality of linear modes is a full-duplex mode.

5. The circuitry of claim 3 wherein the first alpha non-linear mode is a saturated mode.

6. The circuitry of claim 1 further comprising control circuitry adapted to select one of a group consisting of the first alpha mode and the plurality of alpha modes.

7. The circuitry of claim 1 further comprising a first switching power supply adapted to provide an envelope power supply signal, such that the first RF PA stage is further adapted to receive and amplify an alpha driver stage output signal to provide the first RF output signal using the envelope power supply signal.

8. The circuitry of claim 7 wherein the first switching power supply is an envelope tracking power supply.

9. The circuitry of claim 8 wherein the envelope tracking power supply comprises switching circuitry and a parallel amplifier, wherein the switching circuitry is adapted to provide part of the envelope power supply signal and the parallel amplifier is adapted to provide part of the envelope power supply signal.

10. The circuitry of claim 7 further comprising a first DC power supply adapted to provide a first DC power supply signal, such that during the first alpha mode, the second RF PA stage is further adapted to amplify the forwarded first RF output signal to provide a first alpha RF transmit signal via a first alpha harmonic filter using the first DC power supply signal.

11. The circuitry of claim 10 wherein the first DC power supply is a low drop-out (LDO) regulator.

12. The circuitry of claim 10 wherein the first DC power supply is a switching power supply.

13. The circuitry of claim 10 further comprising an alpha driver stage adapted to receive and amplify a first RF input signal to provide the alpha driver stage output signal.

14. The circuitry of claim 13 wherein a DC power source is adapted to provide a DC source signal, such that the alpha driver stage is further adapted to receive and amplify the first RF input signal to provide the alpha driver stage output signal using the DC source signal.

15. The circuitry of claim 14 wherein the DC power source is a battery.

16. The circuitry of claim 13 further comprising a second DC power supply adapted to provide a second DC power supply signal, such that the alpha driver stage is further adapted to receive and amplify the first RF input signal to provide the alpha driver stage output signal using the second DC power supply signal.

17. The circuitry of claim 7 wherein a DC power source adapted to provide a DC source signal, such that during the first alpha mode, the second RF PA stage is further adapted to amplify the forwarded first RF output signal to provide a first alpha RF transmit signal via a first alpha harmonic filter using the DC source signal.

18. The circuitry of claim 7 further comprising an alpha driver stage adapted to receive and amplify a first RF input signal to provide the alpha driver stage output signal using the envelope power supply signal.

19. The circuitry of claim 7 further comprising an alpha driver stage and a n alpha programmable attenuator, such that the alpha programmable attenuator is adapted to receive and attenuate a first RF input signal to provide an alpha driver stage input signal based on a selected one of a group consisting of the first alpha mode and the plurality of alpha modes, and the alpha driver stage is adapted to receive and amplify the alpha driver stage input signal to provide the alpha driver stage output signal.

20. The circuitry of claim 1 further comprising:
a third RF PA stage adapted to provide a second RF output signal;
a fourth RF PA stage; and
a beta RF switch adapted to:
during a first beta mode, forward the second RF output signal to the fourth RF PA stage, such that the third RF PA stage is further adapted to function as a driver stage and the fourth RF PA stage is adapted to function as a final stage; and
during one of a plurality of beta modes, forward the second RF output signal to provide a corresponding one of a group of beta transmit signals, such that the third RF PA stage is further adapted to function as a final stage and the first beta mode is not one of the plurality of beta modes.

21. The circuitry of claim 20 adapted to operate in one of a first PA operating mode and a second PA operating mode, such that during the first PA operating mode, the first RF PA stage, the second RF PA stage, and the alpha RF switch are enabled, and the third RF PA stage, the fourth RF PA stage, and the beta RF switch are disabled, and during the second PA operating mode, the first RF PA stage, the second RF PA stage, and the alpha RF switch are disabled, and the third RF PA stage, the fourth RF PA stage, and the beta RF switch are enabled.

22. The circuitry of claim 20 wherein the first RF output signal is a highband RF output signal and the second RF output signal is a lowband RF output signal.

23. The circuitry of claim 1 further comprising:
a first RF PA comprising the first RF PA stage, which is a first final stage having a first final bias input, such that bias of the first final stage is via the first final bias input;
PA control circuitry;
a PA-digital communications interface (DCI) coupled between a digital communications bus and the PA control circuitry; and
a final stage current digital-to-analog converter (IDAC) coupled between the PA control circuitry and the first final bias input.

24. The circuitry of claim 1 further comprising:
a first RF PA having the first RF PA stage, which is a first final stage, and adapted to:
receive and amplify a first RF input signal to provide the first RF output signal; and
receive a first final bias signal to bias the first final stage;
PA bias circuitry adapted to receive a bias power supply signal and provide the first final bias signal based on the bias power supply signal; and
a direct current (DC)-DC converter adapted to receive a DC power supply signal from a DC p

Assignees

• Rf Micro Devices Inc

Inventors

• Jones David E

Classifications

• H03F2200/537

  A transformer being used as coupling element between two amplifying stages · CPC title

• H03F2200/411

  the output amplifying stage of an amplifier comprising two power stages · CPC title

• H03F2203/21142

  Output signals of a plurality of power amplifiers are parallel combined to a common output · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H03F3/195

  in integrated circuits · CPC title